1. Field of the Invention
The present invention relates to a guitar neck and a method of manufacturing same and, more particularly, to a guitar neck incorporating a truss rod for adjusting the curvature of such neck.
2. Description of the Prior Art
In musical instruments of the type including a body and a neck, such as a guitar, banjo, mandolin, violin and the like, where the instrument neck is made from wood, the neck is subject to warpage from all of the factors which usually cause such phenomenon. Since it is highly important in such an instrument for the fret board to maintain its optimum playing condition, it has become a common practice to provide certain of such instruments with means for adjusting the curvature of the neck to compensate for such warpage.
One of the more common types of adjusting means includes a truss rod assembly positionable in the neck of the musical instrument. A common truss rod assembly is positionable within a slot in the side of the neck opposite from the fret board and includes an elongate truss rod, a fixed anchor nut at one end of the truss rod, and a tension nut at the other end of the truss rod. In operation, rotation of the tension nut moves the other end of the truss rod relative to the tension nut, increasing or decreasing the tension on the truss rod and simultaneously adjusting the curvature of the instrument neck.
The truss rod is an elongate, cylindrical member having a linear axis before being inserted into the slot in the instrument neck, but the slot is curved so that the opposite ends of the truss rod are positioned adjacent the fret board and the center of the truss rod is positioned adjacent the opposite side of the instrument neck. The truss rod assembly is inserted into the slot in the instrument neck and the slot is filled with an elongate fill strip which is made from wood and has the configuration of the slot in the instrument neck after the truss rod assembly is inserted thereinto. The sides of the slot and the fill strip are coated with glue and the fill strip is pressed into the slot. A musical instrument neck having such a truss rod assembly is described in U.S. Pat. No. 4,074,606.
A number of problems have been encountered in use of truss rod assemblies of the above type. First of all, because of the curvature of the slot in the instrument neck and the thickness of the truss rod, the central portion of the fill strip is normally very thin, which creates the possibility of it cracking in handling and failure in use of the instrument. In addition, because of the unevenness of the thickness of the fill strip, the glue, which is used to hold same in the slot, shrinks unevenly. After the fill strip is inserted and the glue dries, the outside surface of the fill strip typically does not align itself exactly with the outside surface of the neck. This necessitates additional finishing and polishing operations which are labor intensive and costly.
In U.S. Pat. No. 4,237,944, to Todd, III et al, a solution to this problem is proposed, which solution consists of forming the neck of a guitar from two similarly shaped blanks of stock material and routing a center portion complementarily formed to accommodate a truss rod. Each element of stock material is routed to provide a mirror image of each other and a separate dowel hole is drilled in each blank to provide further support for the two halves of stock material when they are joined together, as by gluing. The truss rod is preferably J-shaped and is placed in one of the grooves before the blanks are placed together. Subsequent carving of the blanks forms a guitar neck.
While the method of Todd, III et al eliminates the problems associated with the use of fill strips in musical instrument necks, other problems are introduced. By placing a groove on each of the inner faces of each blank in a complementary, associated relationship, two separate and different routing operations are required. A separate locator pin, and holes therefore, is also required. Furthermore, when the two neck blanks are glued together, the plane of the glue joint bisects the truss rod so that the truss rod force operates directly in the plane of the glue joint, which can cause deterioration of same and separation of the neck blanks.